What Does Taking Massive Amounts of Vitamin C Do to Your Body?

by Melodie Anne Coffman

Expect a belly ache if you take a lot of vitamin C.

Vitamin C is a water-soluble vitamin, meaning your system only soaks up what it needs and then flushes out any extra. Because of this, vitamin C is relatively safe at doses well above your recommendation. However, if you take a megadose of the vitamin, you may wind up suffering from several uncomfortable side effects.

Why You Need Vitamin C

Vitamin C is often portrayed as an immune-boosting nutrient, but it is actually essential for your overall health, not just your immune system. You need vitamin C to produce new collagen, a connective tissue that provides elasticity in your skin and aids in wound healing. Vitamin C acts as an antioxidant, fighting off free radicals that damage cells and tissues. When free radicals build up in your system, you increase your chances of developing chronic diseases, including certain types of cancer. Vitamin C also allows your body to absorb plant-based iron, called non-heme iron, and plays a role in metabolizing protein.

Recommendation vs. Unsafe Level

Vitamin C recommendation varies by gender. Men need 90 milligrams per day while women require 75 daily milligrams, reports the Office of Dietary Supplements. During pregnancy and while breast-feeding, women need 85 milligrams and 120 milligrams, respectively. Additionally, if you smoke, you'll have to get another 35 milligrams above your recommendation. You can safely ingest much more without serious complications, but you should limit your intake to less than 2,000 milligrams. Whether you take one large dose or several smaller doses throughout the day, going above this amount may lead to problems.

Minor Negative Effects

Vitamin C is unlikely to cause major health problems if you are generally healthy, even if you take a massive dose well above 100 percent of the daily value of the vitamin. However, since your system will try to flush the excess vitamin C out of your gut, you'll experience gastrointestinal issues. Severe abdominal cramping, bloating, diarrhea and nausea may occur after taking a mega-dose of vitamin C.

More Serious Problems

It is possible to have more serious health implications from large doses of vitamin C up to 10,000 milligrams, although research is inconclusive. When you ingest large quantities of the vitamin, your body absorbs more non-heme iron from plant foods, possibly elevating iron levels in your system. You may be prone to suffering from oxalate kidney stones as well, if you continuously take large doses of vitamin C. Massive doses might even lead to birth defects, decreased antioxidant capabilities and low levels of vitamin B-12, reports the Linus Pauling Institute. It is important to note that these side effects occurred in a small number of people described in independent case reports. Further research is needed to show if these issues were directly related to the megadose of vitamin C or from an underlying health issue.

Drug Interactions

Taking large amounts of vitamin C may interact with some of your prescription medications. If you take a blood thinner or anticoagulant medication, vitamin C can inhibit its function. Your doctor may need to increase the dose of your medication to maximize its potential. Your physician can evaluate how much vitamin C you're getting and determine whether you need to change your prescriptions.

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About the Author

Melodie Anne Coffman has been writing for various online and print publications since 1996, specializing in human and animal nutrition. After receiving her master's degree in food science and human nutrition, she opened up her own nutrition consulting business in the New England area.

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